Frame-and-Panel Construction of the Classic Six-Panel Door

The Frame-and-Panel Door

Six Panel Door. Spiderstock/Getty Images

Frame-and-panel doors use a form of construction in which large floating panels are held within a framework of horizontal rails and vertical stiles. Also called rail-and-stile doors, the advantage of this construction style is that the floating interior panels can shrink and expand with the weather without seriously affecting the overall fit of the door within a cabinet or passageway. Such doors are much less likely to warp or crack. The construction typically uses a basic mortise-and-tenon joinery method, in which narrow tenons shaped into the edges of the panels "float" within mortise slots cut into the edges of the door frame members.

Terminology

A frame-and-panel door is a work of detailed craftsmanship, and there are precise terms used to describe its parts.

Stiles. The stiles are the left and right vertical frame members of the door. They run the full length of the door, from top to bottom, and provide the principal structural strength of the door.

Rails. The rails are the horizontal frame members of the door. They butt into the stiles using mortise-and-tenon joints. A classic six-panel door includes three rails: the top rail, the middle rail (called the lock rail), and the bottom rail.

Mullions. Mullions can be described as the shorter inner stiles that span the gap between horizontal rails. The mullions separate the pairs of floating panels.

Panels: These are the large flat areas of the door that float within the spaces created by the frame members.The panels of a classic six-panel door are usually three pairs of different sizes. For visual balance, the largest panels tend to be in the middle, with the smaller panels at the top and the bottom.

Advantages of Frame-and-Panel Construction

There are distinct structural and stylistic advantages to frame-and-panel construction of doors for cabinets and room passageways:

Structural stability. The frame-and-panel construction provides stability to a wooden door, allowing the large floating panels contained within the framework to expand and contract with changes in humidity. The floating construction prevents cracking and splitting.

Stylistic flexibility. Frames and panels can be arranged in various fashions to maintain consistency with different architectural styles. While the classic six-panel design described here telegraphs a colonial home style, other door styles signify styles such as Craftsman bungalows (six horizontal panels of the same size), Victorian (four panels, paired as two longer upper panels and two shorter lower panels), modern (two relatively large panels), or Arts-and-Crafts (one large upper panel with two narrow lower vertical panels).

Frame-and-panel construction allows a designer a good deal of expression in constructing the door. The inner edges of the frame members may be shaped in any number of architectural profiles, and the inner panels themselves may be shaped so that they are flat, beveled, "raised," or dressed up with the addition of decorative moldings. So popular is this style that flat slab doors are sometimes dressed up with added moldings nailed or glued onto the slab to make them look like panel doors—much the way that "faux" wainscotting can be created on flat walls.

The Classic Six-Panel Door

There are many styles of frame-and-panel door, but one of the most common is the so-called classic six-panel door, which features two smaller upper panels, two long center panels, and two intermediate-sized lower panels. Although this door style is architecturally most appropriate to colonial-style architecture, it is so popular that it is often used (or misused, in the opinion of purists) in homes of entirely different architectural styles.

The classic six-panel door is sometimes known as a cross-and-bible door, due to the apparent symbolism found in the door shape. It does not take too much imagination to see the shape of a Christian cross in the arrangement of the top mullions and intersecting cross rail, and only a slightly bigger leap of imagination to see the bottom two panels as forming the shape of an open book. However, most experts consider this name to be irrelevant to the actual development of the door style, since similar doors are found in older Jewish architectural traditions as well as other non-Christian traditions. More likely, this door style is so popular because it is one of the sturdiest and most durable variations of the frame-and-panel style.

Wood or Non-Wood?

The traditional frame-and-panel door is constructed of solid wood. Such a door is quite expensive, though, and for this reason, non-wood alternatives have become increasingly popular.

Among the non-wood variations are products made from either pressed hardboard or MDF (medium-density fiberboard). While purists might argue that such doors are not authentic, this is not true of many MDF frame-and-panel doors from such companies as TruStile and SUPA. These are doors that use a legitimate frame-and-panel construction, in which the inner panels indeed float within a solid framework of stiles, rails, and mullions.

There are even some advantages to MDF frame-and-panel doors. MDF doors will resist shrinking and expansion even better than traditional solid wood frame-and-panel doors. Because shrinkage is minimal, there is less likely to be the tell-tale line of bare wood around the edges of the inner panels when dry weather causes the panels to shrink slightly. Frame-and-panel doors made from MDF are considerably less expensive than solid wood doors, and tests show them to be just as durable as their solid wood counterparts.